wrote in message
ups.com...
I have a double paned windows with a window airconditioning unit
installed. The unit was profesionally installed. However, the side
panels connecting the frame to the conditioning unit are a flimsy
plastic that allow heat and sound to infiltrate. What is the best way
to insulate the panels from sound and heat loss.

Put an inch or two of foam insulation against them. Can be done on the
outside if you can reach them.